3a^2-(-2a+4a^3+5b)=
(2a-b)+(3a^2-4b^2)=
(3x+y)-(-4x^2+5y^2)=
-2a+(-3b+5c-7d)=
-3a^2-(5a-7b+9b^2)=
(2a-3x)+(-13a+5x)=
-(5,2x-y)+(3,2x-4y)=
(-3x^2+6x+1)-(-2x^2+3x-1)=
-(5a^2-10a+12)-(3a^2+10a-7)=
(-2a+13b)+(2a-13b)=
(1,2a-3,4b)+(-3,2a+0,66)=
. решить надо подробно.

Объяснение:

1. 5x+8y-z= -7, 2.x+2y+z=4,

x+2y+3z=1, 3x-5y+3z=1,

2x-3y+2z=9. 2x+7y-z=8.

3. 3x+2y + z= 5, 4. x+2y+4z=31,

2x+3y+ z =1, 5x+ y+ 2z=29,

2x + y+3z =11. 3x –y+ z=10.

5. 4x-3y +2z=9, 6. 2x-y- z =4,

2x+5y-3z=4, 3x+4y-2z=11,

5x+6y-2z=18. 3x-2y+4z =11.

7. x+ y+2z = -1, 8. 3x-y =5,

2x-y+2z= -4, -2x+ y+ z =0,

4x+ y+ 4z= -2. 2x- y+ 4z=15.

9. 3x –y+ z =4, 10. x+y+z=2,

2x- 5y–3z= -17, 2x-y– 6z= -1,

x+y-z= 0. 3x– 2y= 8.